Blood calcium dynamics after prophylactic treatment of subclinical hypocalcemia with oral or intravenous calcium

Abstract

Total serum Ca dynamics and urine pH levels were evaluated after prophylactic treatment of subclinical hypocalcemia after parturition in 33 multiparous Jersey × Holstein crossbreed cows. Cows were blocked according to their calcemic status at the time of treatment [normocalcemic (8.0-9.9 mg/dL; n = 15) or hypocalcemic (5.0-7.9 mg/dL; n = 18)] and randomly assigned to 1 of 3 treatments: control [no Ca supplementation (n = 11)]; intravenous Ca [Ca-IV (n = 11), 500 mL of 23% calcium gluconate (10.7 g of Ca and 17.5 g of boric acid as a solubilizing agent; Durvet, Blue Springs, MO)]; or oral Ca [Ca-Oral (n = 11), 1 oral bolus (Bovikalc bolus, Boehringer Ingelheim, St. Joseph, MO) containing CaCl2 and CaSO4 (43 g of Ca) 2 times 12h apart]. Total serum Ca levels were evaluated at 0, 1, 2, 4, 8, 12, 16, 20, 24, 36, and 48 h, and urine pH was evaluated at 0, 1, 12, 24, 36, and 4 8h after treatment initiation. Total serum Ca levels were higher for Ca-IV than for control and Ca-Oral cows at 1, 2, and 4h after treatment initiation, but lower than Ca-Oral cows at 20, 24, and 36 h and lower than control cows at 36 and 48 h. At 1h after treatment initiation, when serum Ca levels for Ca-IV cows peaked (11.4 mg/dL), a greater proportion of Ca-IV (n = 8) cows had total serum Ca levels >10mg/dL than control (n = 0) and Ca-Oral (n = 1) cows. At 24h after treatment initiation, when Ca-IV cows reached the total serum Ca nadir (6.4 mg/dL), a greater proportion of Ca-IV (n = 10) cows had serum Ca levels <8 mg/dL than control (n = 5) and Ca-Oral (n = 2) cows. Treatment, time, and treatment × time interaction were significant for urine pH. Mean urine pH was lower for Ca-Oral cows (6.69) than for control (7.52) and Ca-IV (7.19) cows. Urine pH levels at 1h after treatment were lower for Ca-IV cows compared with both control and Ca-Oral cows, a finding likely associated with the iatrogenic administration of boric acid added as a solubilizing agent of the intravenous Ca solution used. At 12, 24, and 36 h, urine pH levels were lower for Ca-Oral cows compared with both control and Ca-IV cows. This was expected because the oral Ca supplementation used (Bovikalc) is designed as an acidifying agent. Wide fluctuations in blood Ca were observed after prophylactic intravenous Ca supplementation. The implications for milk production and animal health, if any, of these transient changes in total serum Ca have yet to be evaluated.

<p>A Pilot Study To Evaluate The Effect Of A Novel Calcium And Vitamin D-Containing Oral Bolus On Serum Calcium Levels In Holstein Dairy Cows Following Parturition</p>

“…10 Another study comparing intravenous (IV) and oral calcium supplementation found that, while IV calcium led to earlier and higher peak serum calcium levels, oral calcium supplementation was associated with higher serum calcium between 20 and 48 hrs post-treatment. 11 Further, treatment with a calcium-containing bolus post calving was associated with a lower incidence of subclinical hypocalcemia, improved pregnancies per breeding, shorter days to pregnancy, and higher milk production in multiparous cows. [12][13][14] Other researchers have found equivocal effects of oral calcium supplementation on serum calcium, health, and reproductive outcomes.…”

Production‐related metabolic disorders of cattle: ketosis, milk fever and grass staggers

“…Blood Ca concentration increases rapidly with intravenous administration, peaking within 15 minutes of administration (Braun and others 2009). Subcutaneous administration is also acceptable for those unable to access a vein; however, time to peak Ca is extended to four hours (Blanc and others 2014, Domino and others 2017). The above treatment will provide the required Ca, and the cow will often stand within 30 minutes of administration.…”

Intravenous calcium infusion in a calving protocol disrupts calcium homeostasis compared with an oral calcium supplement

“…Short-term postpartum management strategies to prevent or treat hypocalcemia are often integrated in farm protocols and include Ca boluses (Sampson et al, 2009), drenches (Goff and Horst, 1993), or voluntarily consumed oral Ca supplements (Geishauser et al, 2008), as well as subcutaneous (Goff, 1999) or i.v. infusions (Blanc et al, 2014). These practices represent a therapeutic intervention more than a prevention strategy, and the implications of these strategies for metabolism and health require consideration.…”

“…Treating cows with i.v. Ca infusions is the most direct intervention method to correct hypocalcemia and is understood to be an easy and inexpensive solution, although it may delay the adaptation of Ca metabolism, even inducing hypocalcemia in initially healthy animals (Martín-Tereso and Martens, 2014;Blanc et al, 2014). Intravenous Ca (11 g of Ca) is therefore not recommended for treating cows that are still standing (Oetzel, 2011).…”

“…Intravenous Ca (11 g of Ca) is therefore not recommended for treating cows that are still standing (Oetzel, 2011). Blanc et al (2014) demonstrated that administration of i.v. Ca infusions (11 g of Ca) to dairy cows at calving resulted in fluctuations of serum tCa concentration that could be detrimental, as the initial stage of hypercalcemia was followed by hypocalcemia 24 h later.…”